集装箱码头装卸作业的调度控制模型及算法设计

对集装箱码头上装卸作业的调度控制直接影响码头的整体运营效率．本文研究了集装箱码头装卸作业的调度控制问题,提出了一个基于柔性化flow shop的集成化控制模型．该问题具有非线性规划(NP：non- polynomial)难度,因此本文开发设计了两类基于优先级规则的启发式调度算法．利用该模型来对码头中多种装卸设备进行总体调度可以提高设备之间的协调性,提高码头效率,降低成本．实验研究证明算法能有效地解决该问题．     

The Non-Erythropoietic EPO Analogue Cibinetide Inhibits Osteoclastogenesis In Vitro and Increases Bone Mineral Density in Mice

The two erythropoietin (EPO) receptor forms mediate different cellular responses to erythropoietin. While hematopoiesis is mediated via the homodimeric EPO receptor (EPOR), tissue protection is conferred via a heteromer composed of EPOR and CD131. In the skeletal system, EPO stimulates osteoclast precursors and induces bone loss. However, the underlying molecular mechanisms are still elusive. Here, we evaluated the role of the heteromeric complex in bone metabolism in vivo and in vitro by using Cibinetide (CIB), a non-erythropoietic EPO analogue that exclusively binds the heteromeric receptor. CIB is administered either alone or in combination with EPO. One month of CIB treatment significantly increased the cortical (~5.8%) and trabecular (~5.2%) bone mineral density in C57BL/6J WT female mice. Similarly, administration of CIB for five consecutive days to female mice that concurrently received EPO on days one and four, reduced the number of osteoclast progenitors, defined by flow cytometry as Lin⁻CD11b⁻Ly6C^hi CD115⁺, by 42.8% compared to treatment with EPO alone. In addition, CIB alone or in combination with EPO inhibited osteoclastogenesis in vitro. Our findings introduce CIB either as a stand-alone treatment, or in combination with EPO, as an appealing candidate for the treatment of the bone loss that accompanies EPO treatment.     

Processing of CaLa2S4 infrared transparent ceramics: A comparative study of HP and FAST/SPS techniques

The densification of CaLa₂S₄ (CLS) powders prepared by combustion method was investigated by the use of Field-Assisted Sintering Technique (FAST) and Hot Pressing (HP). CLS powders were sintered using FAST at 1000°C at different pressures and heating rates and sintered by HP under 120 MPa from 800°C to 1100°C for 6 hours with a heating rate of 10°C/min. Comparison of both techniques was further realized by use of the same conditions of pressure, dwell time, and heating rate. Complementary techniques (XRD, SEM-EDS, density measurements, FTIR spectroscopy) were employed to correlate the sintering processes/parameters to the microstructural/compositional developments and optical transmission of the ceramics. Both sintering techniques produce ceramics with submicrometer grain size and relative density of about 99%. Nevertheless, HP is more suitable to densify CLS ceramics without fragmentation and also reach higher transmission than FAST. Transmission of 40%–45% was measured out of a possible maximum of 69% based on the Fresnel losses in the 8-14 μm window when HP is applied at 1000°C for 6 hours under 120 MPa. In both techniques, ceramics undergo reduction issues that originate from graphitic sintering atmosphere.     

Determination of the mixing performance of sulzer SMV static mixers by laser induced fluorescence

Local concentrations are measured at the outlet of different configurations of Sulzer SMV static mixers placed in a tube. Laser Induced Fluorescence is the non intrusive technique used to measure mean and RMS concentrations. The two fluids mixed are miscible and the flow regime is turbulent. The influence of the number of elements, their position and the ratio between the velocities of the two compounds on the mixing is studied. The results show that these parameters are important for the quality of mixing. The velocity ratio influences the radial mixing, while the mixing length depends on the number and position of the elements.     

Hyperthermostabilization of Bacillus licheniformis{alpha}-amylase and modulation of its stability over a 50{degrees}C temperature range

Bacillus licheniformis     

Individual cell lag time distributions of Cronobacter (Enterobacter sakazakii) and impact of pooling samples on its detection in powdered infant formula

Cells of six strains of Cronobacter were subjected to dry stress and stored for 2.5 months at ambient temperature. The individual cell lag time distributions of recovered cells were characterized at 25 °C and 37 °C in non-selective broth. The individual cell lag times were deduced from the times taken by cultures from individual cells to reach an optical density threshold. In parallel, growth curves for each strain at high contamination levels were determined in the same growth conditions. In general, the extreme value type II distribution with a shape parameter fixed to 5 (EVIIb) was the most effective at describing the 12 observed distributions of individual cell lag times. Recently, a model for characterizing individual cell lag time distribution from population growth parameters was developed for other food-borne pathogenic bacteria such as Listeria monocytogenes. We confirmed this model’s applicability to Cronobacter by comparing the mean and the standard deviation of individual cell lag times to populational lag times observed with high initial concentration experiments. We also validated the model in realistic conditions by studying growth in powdered infant formula decimally diluted in Buffered Peptone Water, which represents the first enrichment step of the standard detection method for Cronobacter. Individual lag times and the pooling of samples significantly affect detection performances.     

Combined effect of high pressure treatment and anti-microbial bio-sourced materials on microorganisms' growth in model food during storage

Antimicrobial bio-sourced films based on poly(lactic acid) containing either carvacrol or allyl isothiocyanate (AITC) were prepared and their antimicrobial properties were assessed on Botrytis cinerea during storage and after a high pressure (HP) “pasteurisation-like” treatment (up to 800 MPa at ambient temperature). A dry process (extrusion + thermomoulding) was used to shape the material. The high temperature encountered during film processing dramatically decreased the carvacrol and AITC content in the film, leading to a less efficient antimicrobial activity. The use of β-cyclodextrin (β-CD) to encapsulate the active compounds before film processing proved to be efficient to protect the AITC against thermal degradation and to control its release from the films during its use. PLA-based films containing either AITC or β-CD encapsulated AITC showed a significant activity against B. cinerea. An effective combination between the antimicrobial activity of AITC-based films and the high pressure treatment was observed on a model food system (PDA) inoculated with N × 10⁴ (N ~ 1–9) conidia of B. cinerea. An HP treatment of only 300 MPa associated with an antimicrobial PLA/β-CD system providing an initial quantity of active agents equivalent to 4 mg of AITC/L of air (i.e. almost 2 folds lower than the minimal inhibition concentration of the active packaging used alone, which was determined to be equal to 10 mg/L of air in the same conditions) was found more efficient (total inhibition of B. cinerea growth during 10 days) than an 800 MPa HP treatment used alone (increase of the lag phase growth of 3.3 days).

Industrial relevance

The consumer demand for “fresh like” product containing reduced amount of preservatives without compromising human and environmental safety needs the development of new preservation strategies. As a consequence, the concept of “hurdle technologies” has risen up. The combined effect of HP treatment and volatile antimicrobial packaging allowed the use of lower individual treatment intensities to inhibit B. cinerea growth. Combining such “hurdles” is of relevance in the context of development of low-cost and eco-friendly food technologies.     

In vitro comparisons between Carica papaya and pancreatic lipases during test meal lipolysis: Potential use of CPL in enzyme replacement therapy

High levels of lipase activity are known to occur in Carica papaya latex, and this activity is being used in some biotechnological applications. The lipolytic activity of C. papaya lipase (CPL) on dietary triacylglycerols (TAG) has not yet been studied. Hence, the aim of this study was to characterise the specific activity of CPL on dietary TAG present in a crude preparation. Also, we have determined its stability during the lipolysis of a test meal at various pH values mimicking those occurring in the gastro-intestinal tract, with or without bile, and have compared these properties with those of porcine pancreatic extract (PPE) and human pancreatic lipase (HPL). CPL showed maximum stability at pH 6.0, both with and without bile. Some residual activity was still observed at pH 2 (20%), whereas the pancreatic lipases tested were immediately completely inactivated at this pH. In the absence of bile, the highest specific activities were measured at pH 6 in the case of CPL, PPE and HPL. Adding bile slightly decreased the CPL activity in the 4–6 pH range, thus shifting the optimum CPL activity to pH 7, where the presence of bile had no effect. Lipolysis levels decreased with the pH, but CPL was still more active than PPE at pH 5 on a relative basis. These results suggest that CPL might be a promising candidate for use as a therapeutic tool on patients with pancreatic exocrine insufficiency.